NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: SOA vs SMG or SOG
From: Richard M Pisko
Date: 2009 Oct 28, 11:06 -0600
From: Richard M Pisko
Date: 2009 Oct 28, 11:06 -0600
On Tue, 27 Oct 2009 15:35:52 -0600, QMCMwrote: > It was in thanks for using > several of my articals and introducing The Franklin Piloting, The > Graduated perpendiclar bisector, for the three point problem (Sextant) I read your message #9304, but did not see any of the diagrams. My only Bowditch is 1995. I'm interested in resecting my position from three points, mostly from the plane table. I hadn't seen any instrument that would make it easier, other than a three arm protractor or purpose drawn intersecting angle chart overlays. Protractors are getting a bit expensive. Is a picture of your bisector available, with instructions? Trial and error in making the triangle smaller on a plane table map is pretty quick, if you understand the direction and amount each line will move when rotating the table for a new round of sights. Two rounds usually gives a very good position, +/- 2 or 3 hundredths of an inch on the map; depending on the "goodness" of the angles to the reference points. -- Richard . . . Using Opera 9.2.4 after the "Dog" died --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList+@fer3.com -~----------~----~----~----~------~----~------~--~---